There is known GEOTHERMAL HEAT TRANSFER SYSTEM U.S. Pat. No. 4,993,483 to Harris for a geothermal system that uses a cylindrical tube filled with sand or concrete to encase a return loop for exchanging heat with the earth.
There is also known A GEOTHERMAL DIRECT EXPANSION HEAT PUMP SYSTEM U.S. Pat. No. 5,671,608. The invention is a copper ground loop piping that is used as a ground exchanger, with refrigerant released at low pressure. Rather than use water or a glycol mix, as in the traditional geothermal heat exchange systems, this invention uses a refrigerant to exchange heat with the ground.
There is also known A BURIED VERTICAL SCREW-SUNK HEAT EXCHANGER FOR A HEATING OR COOLING INSTALLATION PCT/FR2008/051168. The invention is a steel pipe filled with water/glycol mix and re-circulated by a pump to exchange with ground energy and bring heat up from the ground.
The present invention relates to an optimization of traditional geothermal systems, direct expansion system and the screw-sunk heat system. The results of using the present invention are increased efficiency in extracting latent heat from the ground. This increase is partially as a result of the combination of the present invention's large dissipation capacity with low temperature variance distribution. The heat exchanger of the present invention incorporates two channels for exchange fluid, one channel for going up, and one channel for going down. The present exchanger housing is made of aluminum, and could be made in different diameters to optimize contact with the geothermal well in the ground.
Aluminum has a heat transfer coefficient of about 200 W/m·K, and is more efficient to carry the potential energy from the ground than concrete, whose heat transfer coefficient is about 2 W/m·K. The adiabatic-isothermal.
heat sink exchanger is superior to present art due to the fact that it is more beneficial to exchange heat using an exchanger with a large circumference instead of two smaller circumferences.
However, the present invention is not restricted to aluminum only, and any other similar materials, such as magnesium or other known substances having high heat transfer could also be used. The resulting effect is that this exchanger's loop can bring up more heat out of the ground thanks to its surface area that is in contact with the ground inside the well.
The advantages of the present invention are numerous: material costs are brought down to a minimum. The exchanger is extruded from aluminum in pre-determined lengths. The preferred embodiment comprises 20-foot lengths, allowing to make 40-foot, 60-foot, or any multiple of 20-foot exchangers desired. Installation is simplified by the fact that the exchanger is delivered in 20-foot sections that are joined at the installation site. Continuity of fluid flow between sections is assured by the present embodiment's pipe joint fittings; joints can be sealed immediately prior to installation of the exchanger into the ground.